1. Technical Field
This disclosure generally relates to the field of electrotherapy and, more particularly, to system, devices, and methods for providing non-transcranial electrotherapy to a biological subject.
2. Description of the Related Art
The term temporomandibular joint (TMJ) disorder, sometimes referred to as temporomandibular disorder, TMJ syndrome, or myofacial pain dysfunction syndrome, encompasses a whole spectrum of conditions and diseases associated with pain and/or dysfunction in the jaw joint and the muscles that control jaw movement. These conditions and diseases include injured or damaged tissues affecting the function of the TMJ, discomfort or pain in the muscles that control jaw function, displacement of a TMJ disc, a dislocated jaw, an injury to the condyle, derangements of the articulating elements in the TMJ, degenerative or inflammatory joint disorders, progressive degenerative and very painful breakdown of TMJ cartilage, tenderness and pain of the TMJ, and pivoting of the jaw. It has been estimated that about 8 to 15 percent of women and about 3 to 10 percent of men experience pain associated with TMJ disorder. There are no known cures for TMJ disorder.
Conventional conservative treatments for TMJ disorder include eating soft foods, applying ice packs, avoiding extreme jaw movements, learning techniques for relaxing and reducing stress, as well as short-term use of over-the-counter pain medicines, nonsteroidal anti-inflammatory drugs, muscle relaxants, or anti-depressants. Conventional conservative treatments often provide only temporary pain relief.
Conventional irreversible TMJ disorder treatments include surgery, orthodontics to change the bite, crown and bridge work to balance the bite, grinding down teeth to bring the bite into balance, and repositioning splints (e.g., orthotics), which permanently alter the bite. Surgical treatments, such as the replacement of jaw joints with artificial implants, are often irreversible and in some cases may cause severe pain and permanent jaw damage. For example, some artificial implants may fail to function properly or may break apart in the jaw over time.
Bone and other tissues such as cartilage respond to electrical signals in a physiologically useful manner. For example, electric and electromagnetic fields regulate extra-cellular matrix synthesis and stimulate repair of fractures and nonunions. Other less well-known outcomes attributed to bioelectrical stimulation are positive bone density changes (Tabrah, 1990), and prevention of osteoporosis (Chang, 2003). A recent report offered adjunctive evidence that stimulation with pulsed electromagnetic field (PEMF) significantly accelerates bone formed during distraction osteogenesis (Fredericks, 2003).
A disadvantage of most electrotherapeutic devices now available, however, is that they often rely on direct implantation of electrodes (or entire electronic packages), or they rely on inductive coupling through the skin using coils which generate time-varying magnetic fields, thereby inducing weak eddy currents within body tissues which inefficiently provide the signal to tissues. Consequently, in addition to bulky coils these systems require relatively large signal generators and battery packs. The need for surgery and biocompatible materials in the one case, and excessive circuit complexity and input power in the other, has kept the price of most such apparatus relatively high, and has also restricted the application of such devices to highly trained personnel. Further, it is noted that TENS (Class II) medical devices are contra-indicated for use on the head.
Accordingly, there remains a need for a versatile, cost-effective system that can be used to provide bioelectric stimulation in a wide range of applications, including healing acceleration and pain relief. There is also a need in the art for a bioelectric stimulation system that is power efficient, capable of being powered by safe, low-voltage batteries, and can reduce the likelihood of a shock hazard.
The present disclosure is directed to overcoming one or more of the shortcomings set forth above, and/or providing further related advantages.